CVE-2023-30583
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedfs.openAsBlob() can bypass the experimental permission model when using the file system read restriction with the `--allow-fs-read` flag in Node.js 20. This flaw arises from a missing check in the `fs.openAsBlob()` API. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn Node.js 20, the experimental permission model intended to restrict file system access via --allow-fs-read can be bypassed through the fs.openAsBlob() API due to a missing authorization check. This allows code with limited file read permissions to access files it should not be able to read, circumventing the security boundary that the experimental permission model is designed to enforce.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Node.js versionRun 'node --version' to determine the installed Node.js versionAffected if Version is 20.x (any minor version within the 20 line)
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Verify permission model is activeCheck if the Node.js process was launched with --allow-fs-read flag by reviewing startup scripts, Docker CMD/ENTRYPOINT, or process argumentsAffected if The --allow-fs-read permission flag is being used to restrict file system access
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Detect fs.openAsBlob usageSearch codebase for 'fs.openAsBlob' API calls using grep or IDE search: grep -r 'openAsBlob' or inspect application source codeAffected if The application code calls fs.openAsBlob() to read files
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Confirm bypass conditionIf Node.js 20 is running with --allow-fs-read permission model AND fs.openAsBlob() is used, the authorization check is bypassedAffected if All three conditions are true: Node.js 20.x, --allow-fs-read enabled, and fs.openAsBlob() API in use
You are affected if running Node.js 20.x with the experimental permission model (--allow-fs-read) and your code uses the fs.openAsBlob() API, which can read files outside the allowed paths.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataAvoid using the experimental permission model in production environments until it reaches stable status. If currently using --allow-fs-read with the permission model, be aware that fs.openAsBlob() can bypass these restrictions and monitor for Node.js updates that address this vulnerability.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2023-30583 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-30583 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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